Как изменить цвет svg иконки при наведении?

Как вариант

import sys
from PyQt5.QtWidgets import (QRadioButton, QHBoxLayout, QButtonGroup, 
    QApplication, QWidget)
from PyQt5.QtGui import QIcon, QPixmap
from PyQt5.QtCore import QSize, Qt
from PyQt5 import QtCore, QtGui, QtWidgets

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtSvg import QSvgWidget, QSvgRenderer
from base64 import b64encode


def iconFromBase64(base_64):
    pixmap = QtGui.QPixmap()
    pixmap.loadFromData(QtCore.QByteArray.fromBase64(base_64), "SVG")
    icon = QtGui.QIcon(pixmap)
    return icon


class RadioButton(QRadioButton): 
    def __init__(self, icon, parent=None):
        super(RadioButton, self).__init__(parent)
#        print(icon)

        self._pixmap = QtGui.QPixmap()
        self.setSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
        self.setText('rb0')
        self.setIcon(icon[1])
        self.setIconSize(QSize(50, 50))

    @QtCore.pyqtProperty(QtGui.QPixmap)
    def pixmap(self):
        return self._pixmap

    @pixmap.setter
    def pixmap(self, pixmapPath):
        self._pixmap = QtGui.QPixmap(pixmapPath)

    def paintEvent(self, event):
        opt = QtWidgets.QStyleOptionButton()
        self.initStyleOption(opt)
        qp = QtGui.QPainter(self)   
        # нарисовать основную кнопку        
        self.style().drawControl(QtWidgets.QStyle.CE_PushButtonLabel, opt, qp, self)

        if self._pixmap.isNull():
            return   

    def enterEvent(self, e):
        self.setText("red!")
        self.window().svgColor("#f00")
        svg_base64_str = b64encode(self.window().svg_str.encode('utf-8'))      
        self.icon = iconFromBase64(svg_base64_str)
        self.setIcon(self.icon)
        super().enterEvent(e)   

    def leaveEvent(self, e):
        self.setText("blue")
        self.window().svgColor("#00f")
        svg_base64_str = b64encode(self.window().svg_str.encode('utf-8'))      
        self.icon = iconFromBase64(svg_base64_str)
        self.setIcon(self.icon)       
        super().enterEvent(e)


class Window(QWidget):
    def __init__(self):
        super().__init__()

        self._dictRB = {                                            
            'rb0': False,
            'rb1': False,
            'rb2': False,
            'rb3': False,
        }

        self.main_layout = QHBoxLayout(self)
        self.buttonGroup = QButtonGroup()
        self.attr_layout = QHBoxLayout()
        self.main_layout.addLayout(self.attr_layout)

# ++        
        self.svgColor("#00f")        
        svg_base64_str = b64encode(self.svg_str.encode('utf-8'))      
        self.icon = iconFromBase64(svg_base64_str)          

        self.rb0 = RadioButton(["2.svg", self.icon], self)         
# ++       
        self.attr_layout.addWidget(self.rb0)
        self.buttonGroup.addButton(self.rb0)

        self.rb1 = QRadioButton('rb1')
        self.attr_layout.addWidget(self.rb1)
        self.buttonGroup.addButton(self.rb1)               
        self.rb2 = QRadioButton('rb2')
        self.attr_layout.addWidget(self.rb2)
        self.buttonGroup.addButton(self.rb2) 
        self.rb3 = QRadioButton('rb3')                               
        self.buttonGroup.addButton(self.rb3)                         
        self.buttonGroup.buttonClicked.connect(self.check_button)

    def check_button(self, radioButton):
        '''
        if self._dictRB[radioButton.text()]:
            self._dictRB[radioButton.text()] = False
            self._dictRB['rb3'] = True
            self.rb3.setChecked(True)              
        else:
            for b in self._dictRB:
                self._dictRB[b] = False
            self._dictRB[radioButton.text()] = True
        '''
        print("Нажата кнопка -> `{} - {}`".format(radioButton.text(), radioButton.isChecked()))

# ++        
    def svgColor(self, color):
        self.svg_str = """        
        <svg width="141.111mm" height="141.111mm"
         viewBox="0 0 400 400"
         xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"  version="1.2" baseProfile="tiny">
        <title>Qt SVG Document</title>
        <desc>Generated with Qt</desc>
        <defs>
        </defs>
        <g fill="none" stroke="black" stroke-width="1" fill-rule="evenodd" stroke-linecap="square" stroke-linejoin="bevel" >

        <g fill="%s" fill-opacity="1" stroke="none" transform="matrix(1,0,0,1,0,0)"
        font-family="MS Shell Dlg 2" font-size="8.25" font-weight="400" font-style="normal" 
        >
        <rect x="0" y="0" width="400" height="400"/>
        </g>

        <g fill="#808080" fill-opacity="1" stroke="#ffffff" stroke-opacity="1" stroke-width="1" stroke-linecap="square" stroke-linejoin="bevel" transform="matrix(1,0,0,1,0,0)"
        font-family="MS Shell Dlg 2" font-size="8.25" font-weight="400" font-style="normal" 
        >
        <rect x="100" y="100" width="200" height="200"/>
        <text fill="#ffffff" fill-opacity="1" stroke="none" xml:space="preserve" x="193" y="203" font-family="MS Shell Dlg 2" font-size="8.25" font-weight="400" font-style="normal" 
         >test</text>
        </g>
        </g>
        </svg>        
        """ % color


if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = Window()
    w.show()
    sys.exit(app.exec_())